Secondary adsorption of phosphate on aluminum oxides surfaces as influenced by several organic acids

Abstract

Synthetic aluminum (Al) oxides (with or without different organic acids and inorganic anions) were used to study the effect of organic acid on phosphate secondary adsorption. The results showed that the maximum of phosphate adsorption (Xm) for the six Al oxides were 0.189-0.838 mmol/g in the absence of other organic acid. The Al(OH)x sample, which was synthesized without additional ligands, had the greatest Xm among these Al oxides, whereas, the Al(OH)x-CA sample, which was synthesized in the presence of citrate, had the least Xm. For most samples, the higher the addition concentrations of organic acids were, the greater the magnitude of phosphate secondary adsorption reduction was. However,..